Locomotive with sanding system having continuous air flow



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United States Patent M 3,345,097 LOCOMOTIVE WITH SANDING SYSTEM HAVING CONTINUOUS AIR FLOW Harold L. Smith, La Grange, Ill., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Mar. 19, 1965, Ser. No. 441,008 12 Claims. (Cl. 291--3) This invention pertains to a system for supplying sand to the traction drive means of a railway locomotive to increase its traction.

It' is common practice to provide railway locomotives with a sanding system in which air under relatively high pressure forces sand through a delivery conduit to the point of contact between the locomotive wheel and the track. Difficulty is frequently encountered with such sanding systems because the discharge end of the delivery conduit is disposed close to the ground and often becomes obstructed by mud or snow between sanding operations. In addition, such systems require an engine driven compressor which takes considerable power, reducing the economy of locomotive operation.

This invention is directed to a new sanding system designed to overcome these difficulties. The new sanding system provides a continuous flow of air under relatively low pressure through the sand delivery conduits. Such a flow of air removes material which would otherwise accumulate to obstruct the conduits. A blast of air under high pressure is no longer necessary to free the delivery conduits of obstruction during each sanding operation.

This same flow of air may be utilized to carry sand to the wheels whenever sanding is desired. In one embodiment of this invention, the sand is released directly into the air flow where it will be entrained and carried through the delivery conduit.

A supply of low pressure air is readily available on the majority of existing locomotives. These locomotives, driven from the engine by a generator and electric traction motors, have an engine driven blower to supply cooling air for ventilating the traction motors. This blower provides suflicient air to also maintain a continuous air flow through the sand delivery conduits. Such an air flow will maintain the sanding system unobstructed and operative without a substantial drain of engine power.

Sand released directly into the air flow in the delivery conduits will be entrained and delivered to the wheels. In some situations, however, the air flow provided by the blower at lower engine speeds may be insufiicient to entrain the amount of sand necessary for traction. This invention therefore also provides means to supplement the low pressure air flow with air from the high pressure reservoir. The amount of air required to supplement the flow from the blower is low and is required only at lowspeeds so that even this sanding system does not significantly drain the power output of the engine.

In addition to these advantages, a low pressure sanding system requires less maintenance than the existing systems. For example, a sanding system supplied from a high pressure air reservoir requires a series of orifices and valves which become plugged from dirt and oil in the air. Such systems can remain fully operative only through frequent maintenance work. On the other hand, a low pressure sanding system using an engine driven blower requires supplementary high pressure air only infrequently and thus substantially reduces the maintenance requirement of the sanding system.

This invention also increases the period of time over which sand may be delivered to the track. In some instances, sanding time was heretofore limited by the capacity of the high pressure air reservoir and the demands imposed by the air brakes and other pneumatic 3,345,097 Patented Oct. 3, 1967 safety devices. By this invention, however, a relatively unlimited supply of low pressure air is made available for sanding. The greater supply of air permits delivery of sand to the track over as extended a period of time as may be desired.

The details as well as other objects and advantages of this invention are disclosed in the following description and in the drawing in which:

FIGURE 1 illustrates a locomotive showing in outline form the components utilized to provide a low pressure sanding system;

FIGURE 2 illustrates a locomotive sanding system in which a continuous low pressure air flow is supplied from the traction motor ventilating system; and

FIGURE 3 illustrates an electrical circuit for operating the system shown in FIGURE 2.

Referring first to FIGURE 1, a locomotive L includes an engine E which drives a generator G to supply power to traction motors M. The motors M drive wheel W to propel locomotive L along a track T. Engine E also drives an auxiliary generator AG which, in connection with a voltage regulator (not shown), maintains a constant low voltage supply. A blower B is driven by engine E to supply a plenum chamber 10 with air under low pressure. Air flows from chamber 10 through flexible connections 11 to cool the traction motors M. An air compressor C is also driven by engine E to maintain a reservoir R under relatively high pressure, for example, pounds per square inch (a gauge pressure of approximately ten atmospheres), to operate the locomotive air brakes and other safety devices not shown).

The sanding system provided by this invention for locomotive L includes a sand storage container 12 from which sand may be delivered through a conduit 14 to the point of contact between the wheel W and the track T. Conduit 14 extends from a sand trap 16 located beneath container 12. A transfer device 18 is interposed between container 12 and trap 16 and, upon actuation, transfers sand from container 12 to sand trap 16.

Referring now to FIGURE 2, air plenum chamber 10 is maintained at relatively low pressure by blower B. In one locomotive model presently in service, the pressure in chamber 10 varies with engine speed and is in the range between two and fourteen inches of water or between approximately 0.07 and 0.5 pound per square inch (a gauge pressure less than two atmospheres). Flexible connections provide a passage through which air flows from chamber 10 to ventilate and cool traction motors M. A connection 22 between chamber 10 and trap 16 allows air from chamber 10 to fiow continuously through trap 16 and conduit 14 to maintain conduit 14 free of obstruction. When transfer device 18 is actuated and sand is transferred from container 12 to sand trap 16, the flow of air through the trap entrains the sand and delivers it through conduit 14 to wheel W to increase traction.

Since the traction motor blower B is driven by the engine E, its speed varies with engine speed, and at lower engine speeds the pressure of air in plenum chamber 10 may be insufficient to provide proper sanding. To supplement the flow of air from chamber 10, a line 24, 25 is provided which extends from the high pressure reservoir R and discharges into conduit 22. A valve 26 controls discharge from reservoir R through line 24, 25 to supply high pressure air only when sanding is required at low engine speeds.

It will be appreciated that many different types of structures may be utilized to put this invention into practice. As shown in the copending application Ser. No. 441,047, filed Mar. 19, 1965 by Harry A. Kilgore and Harold L. Smith, the transfer device 18 comprises a vibratory feeding trough driven by a pulse generator to supply and meter the sand to trap 18. FIGURE 3 illustrates an electrical arrangement for operating such a transfer device. As shown therein, a pulse generator 28 is connected across a voltage source V which may be supplied by the auxiliary generator AG. Pulse generator 28 operates continuously, and when sanding is required, the locomotive operator closes a normally open switch 30 to energize a relay 32. Relay 32 closes its normally open interlock 34 to supply the generated pulse from generator 28 to the vibratory transfer device 18. Transfer device 18 will supply sand from storage container 12 to trap 16 for delivery through conduit 14.

An interlock 36 is controlled by the engine governor to close at low engine speeds when the pressure in chamber and the air flow through trap 16 and conduit 14 is low. Then when switch is closed by the operator, a relay 38 will be energized to open valve 26 and admit a supplementary air flow from reservoir R.

The sanding system thus disclosed and described provides a significant improvement in operation over those presently available on railway locomotives. The entire system is kept free of obstruction without substantial maintenance work, and the system is available for operation under all conditions without an excessive drain of power from the engine.

I claim:

1. A railway locomotive including wheels adapted to roll along a track, wheel driving means to propel said locomotive, air plenum chamber means connected to said wheel driving means, blower means pressurizing said chamber means to cause a flow of cooling air to said driving means, and a system for supplying sand to said wheels to increase traction, said system comprising a delivery conduit, means connecting said air plenum chamber means and said delivery conduit to provide a continuous flow of air from said chamber through said conduit to maintain said conduit free of obstruction, and means actuable to cause air flow from said chamber to deliver sand through said conduit, said conduit being oriented to direct sand for delivery to the tread of at least one of said wheels.

2. The locomotive of claim 1 wherein said driving means comprises an engine, a generator, means connecting said generator to said engine to thereby drive said generator, a traction motor, and means connecting said motor to said generator whereby said motor is powered by said generator, and wherein said plenum chamber means supplies cooling air to said traction motor.

3. The locomotive of claim 1 which further includes a reservoir and air compressor means pressurizing said reservoir to a pressure significantly higher than the pressure of said air plenum chamber means and wherein said system further comprises means connecting said reservoir and said conduit actuable to cause an additional flow of air from said reservoir through said conduit when the air flow from said chamber is otherwise insufiicient to deliver sand through said conduit.

4. A railway locomotive including wheels adapted to roll along a track, a traction motor adapted to drive said wheels, an engine and generator adapted to drive said motor, an air plenum chamber, a blower driven by said engine and maintaining said chamber at a first pressure by said blower, means to ventilate said motor from said chamber, and a system for supplying sand to said wheels to increase traction, said system comprising a sand trap, 21 delivery conduit from said trap, means connecting said chamber and said trap to cause a continuous flow of air from said chamber through said trap and conduit to maintain said conduit free of obstruction, a sand storage container, first means actuable to deliver sand from said container to said sand trap for entrainment in the air flow through said sand trap and delivery through said conduit,

said conduit being oriented to direct sand for delivery to the tread of at least one of said wheels, said locomotive further including an air reservoir maintained at a second pressure significantly higher than said first pressure, and said system further comprising means connecting said reservoir and said trap including valve means actuable coincidentally with said first means to admit an additional flow of air from said reservoir to said trap.

5. A railway locomotive including wheels adapted to roll along a track and a system for supplying sand to said wheels to increase traction, said system comprising a conduit, an air plenum chamber, blower means maintaining said chamber at gauge pressures less than about two atmospheres, means connecting said air plenum chamber and said conduit to provide a continuous fiow of air from said chamber through said conduit to maintain said conduit free of obstruction, and means actuable to cause air flow from said chamber to deliver sand through said conduit, said conduit being oriented to direct sand for delivery to the tread of at least one of said wheels.

6. The locomotive of claim 5 which further includes wheel driving means and means connecting said wheel driving means to said air plenum chamber to supply air to said wheel driving means.

7. The locomotive of claim 5 which further includes wheel driving means and means connecting said wheel driving means to said air plenum chamber to supply cooling air to said wheel driving means.

8. The locomotive of claim 7 wherein said wheel driving means includes rotating electrical equipment and wherein the cooling air is supplied to said equipment.

9. The locomotive of claim 8 wherein said rotating electrical equipment includes a traction motor and wherein the cooling air is supplied to said motor.

10. The locomotive of claim 5 which further includes an air reservoir maintained at pressures significantly higher than the pressures in said air plenum chamber and wherein said system further comprises means connecting said reservoir and said conduit to cause an additional flow of air from said reservoir through said conduit when the pressure in said chamber is insufficient to cause air flow from said chamber to deliver sand through said conduit.

11. The locomotive of claim 10 wherein said air reservoir is maintained at gauge pressures on the order of ten atmospheres.

12. The locomotive of claim 10 wherein said means connecting said air plenum chamber and said conduit includes a sand trap from which said conduit extends and an air flow conduit extending from said chamber to said trap whereby said chamber provides a flow of air through both said trap and said conduit to deliver sand through said conduit and wherein said means connecting said reservoir and said conduit comprises a supplementary air flow line extending into said air flow conduit upstream of said trap.

References Cited UNITED STATES PATENTS 940,025 11/1909 Johndrow 2913 1,486,578 3/1924 Harney 29l1 2,030,669 2/1936 White 29l3 2,232,915 2/1941 Hewitt 29 l3 2,589,794 3/1952 FrantZ 251-62 2,669,472 2/1954 Harms 29l5 2,672,361 3/1954 Werbe 291-3 3,116,700 1/1964 Aydelott 59 ARTHUR L. LA POINT, Primary Examiner. H. BELTRAN, Assistant Examiner. 

1. A RAILWAY LOCOMOTIVE INCLUDING WHEELS ADAPTED TO ROLL ALONG A TRACK, WHEEL DRIVING MEANS TO PROPEL SAID LOCOMOTIVE, AIR PLENUM CHAMBER MEANS CONNECTED TO SAID WHEEL DRIVING MEANS, BLOWER MEANS PRESSURIZING SAID CHAMBER MEANS TO CAUSE A FLOW OF COOLING AIR TO SAID DRIVING MEANS, AND A SYSTEM FOR SUPPLYING SAND TO SAID WHEELS TO INCREASE TRACTION, SAID SYSTEM COMPRISING A DELIVERY CONDUIT, MEANS CONNECTING SAID AIR PLENUM CHAMBER MEANS AND SAID DELIVERY CONDUIT TO PROVIDE A CONTINUOUS FLOW OF AIR FROM SAID CHAMBER THROUGH SAID CONDUIT TO MAINTAIN SAID CONDUIT FREE OF OBSTRUCTION, AND MEANS ACTUABLE TO CAUSE AIR FLOW FROM SAID CHAMBER TO DELIVER SAND THROUGH SAID CONDUIT, SAID CONDUIT BEING ORIENTED TO DIRECT SAND FOR DELIVERY TO THE TREAD OF AT LEAST ONE OF SAID WHEELS. 